How does the power of a servo affect the flight.

[noobie]

I am quite new to buying a ARF so how does a 7G servo affect flight compared to a 5G servo.

P.S. How many servos do you need for a plane.

[chris.7935]

Those numbers dont tell you anything about what you are asking about. THey are the WEIGHT of the servo.

You need to look at the travel spped and torque settings on the servo. In both cases more is always better.

[dallasflyfisher]

How many servos in a plane is dependent on the plane. Here is a general guide for electrics and nitros
2 Servos for planes that work on Elevons, these are planes like flying wings, some jets, V-Tails, etc (need a 3rd servo if you are using gas so you have throttle control)
3 Servos for planes that use a single servo for Ailerons, Elevator, Rudder (add a 4th servo if your flying gas again for the throttle or using an electric Variable Pitch Prop *VPP*)
4 Servos for planes that you want to use Flaperons which means each aileron has it's own servo that can act independently of each other.  These set ups give you the ability to use flaps (add 5th servo for gas planes throttle or VPP)
5+ servos if you start adding things like servo actuated landing gear, air brakes, bomb doors, some larger planes can use 2 servos for each control surface due to their size or weight.

[VROOM]

The number of servos depends on the number of channels on the plane your using. 2 channel is throttle (that doesnt use a servo) and then a single servo to run the rudder. 3 channel planes will use a 2nd servo to operate the elevator. 4 channel planes can use the 4th channel for either ailerons/steerable nose gear or a bomb dropper and that requires an additional servo.

So it just depends on the plane you purchase on how many servos it takes.

When purchasing a servo the main things to consider are the torque rating and the transit speed. The weight of the servo is not as important unless your putting them into a lightweight plane. But be aware. Using a set of lighter or heavier servos then stock can set the "center of gravity" (COG) off. But that can easily be compensated for by adding, removing or shifting weight from other parts of the plane.